The subject matter disclosed herein relates generally to imaging systems, and more particularly to nuclear medical imaging systems having multi-head detectors.
In nuclear medicine (NM) imaging, such as single photon emission computed tomography (SPECT) or positron emission tomography (PET) imaging, radiopharmaceuticals are administered internally to a patient. The radiopharmaceuticals emit radiation that may be captured by an NM imaging system to generate images for diagnostic review. The NM imaging system may be configured as a multi-head system having a number of individual detectors (or gamma cameras) that are distributed about a bore of the gantry. The detectors are spaced apart from each other such that gaps exist between adjacent detectors. Each detector may be configured to move to provide a range over which the detector may acquire image data.
Prior to the imaging session in which the diagnostic images are obtained, the patient is positioned relative to the detectors so that a collective field-of-view of the NM imaging system includes the anatomical region of interest (e.g., heart, brain, etc.). At this time, one or more persistence images are obtained and reviewed to position the patient. The persistence images are typically only used to position the patient and, as such, have a lower quality than the images used for diagnosis. Persistence images may be acquired at a frequency of, for example, one image per second or less. As the images are acquired, the technician reviews the images and incrementally moves the patient within the bore of the gantry so that the anatomical region-of-interest is within the collective field-of-view. It is generally desirable to quickly position the patient, because the emissions from the radioisotopes reduce over time. During the time in which persistence images are acquired, a technician may also assess the activity of the radioisotopes for determining the scan duration
It can be challenging, however, to use persistence images from multi-head imaging systems. For example, gaps may exist between adjacent detectors thereby rendering it more difficult to identify the anatomical region of interest in the persistence images. This process is made even more difficult for field-of-views that are only slightly larger than the anatomical region of interest.